The Gas and Aerosol Monitoring Sensorcraft (GAMS) concept is an outgrowth of a "Stratospheric Aerosol and Gas Experiment (SAGE) IV" technology development study and a successful 1995 New Millenium Program (NMP) instrument technology proposal (Gas and Aerosol Monitor of the Upper Troposphere - GAMUT). The term sensorcraft simply designates a space flight remote sensing system that does not distinguish between the instrument, which performs a remote measurement, and the spacecraft bus, which provides the operational resources needed by the instrument in orbit. The sensorcraft integrates the resource requirements of both to minimize size, power consumption and cost. The central theme for GAMS is, 'How to make core climate measurements in a cost effective, sustainable manner.' Solar occultation is undeniably the premiere method for making long-term, decadal measurements of aerosols, ozone and other trace species which can be utilized in the detection of global trends in the vertical distribution of these species. GAMS takes this robust and well demonstrated capability to the next level beyond SAGE III by improving the quality of the measurements and extending them down into the mid and upper troposphere. At the same time GAMS will significantly reduce total mission costs through the use of new hardware and software technologies which allow for complete autonomy and a virtual elimination post-launch operational costs (MO&DA). These savings will allow the implementation of a fleet approach to overcome the limitations of a single satellite taking months to achieve global coverage. GAMS will make significant contributions to Office of Earth Science Research Plan research areas as follows:

The overall success of this proposal does not require that every technology being developed becomes viable. Some of the technologies being advanced here have proven technologies which can be used in case of problems. Use of these matured technologies, however, will have significant impacts on the overall system and would certainly alter the detailed design of GAMS. If all technologies are successfully developed and integrated into GAMS, we see the lowest cost Phase D deployment of GAMS as a sensorcraft. If instead, GAMS is included in a combined mission on a larger traditional spacecraft, the GAMS instrument design could include a subset of these technologies with little or no loss of capability, but at an increased total mission cost.

This proposal focuses on the development and demonstration of those functions specific to the science instrument and flight data processing hardware and software. It does not include any development or costs for those systems traditionally delegated to the spacecraft functions. While GAMS was intended and ideally suited for deployment as a dedicated sensorcraft, the instrument could be built as a traditional "bolt-on" entity. Also, the spacecraft functions and required levels of performance are not considered to be technical "tall poles". The entry point for this two-year proposal is the preliminary design/laboratory breadboard stage and the exit point is the engineering model/field demonstration stage. Engineering models (full function but not to form or fit) will be developed and field demonstrations/simulated environment tests will be conducted on key high-risk GAMS subsystems. Furthermore, this work will demonstrate the concept feasibility and hard/software functionality at the level required to proceed with confidence into an 18 month Phase D development.